The present invention relates to the field of insect traps and particularly relates to a container defining a foraminous sub-enclosure within a trap, holding an olfactory lure for attracting insects to the trap.
Insects are trapped for various purposes such as to kill them, count them or trap themalive for testing or the like. Attractive scents and colors can be used for this purpose, relying upon instinctive urges of the insects to seek food or reproduction. Food scents and sexually attractive pheromones are released inside or adjacent a trap such that insects in the area are drawn to the trap. Traps are known and have been specifically configured, for example, to trap boll weevils, gypsy moths, Japanese beetles, Mediterranean fruit flys, and other insects. In some agricultural situations, traps are used on a very large scale, with large numbers being deployed over an area to be protected or monitored.
One of the more popular methods to trap the Mediterranean fruit fly, an insect that attacks citrus trees, is to use a pheromone lure to draw flys into a trap, where they die and can be counted. One form of such trap, called the Jackson trap or delta trap, is characterized by a tube of triangular cross section, and means for removing a wall to check for and remove dead flys. Currently, an attractant lure is placed on a dental wick that is attached to a metal holder disposed inside the trap. The wick is saturated with a prescribed amount of lure and placed in the trap. The lure preferably acts as an insecticide as well as an attractant, for killing or disabling the insects. Alternatively, a separate means for killing the insects can be provided. The trap must be re-baited from time to time when the lure's olfactory characteristic diminishes, for example when most of the volatile material carrying the scent evaporates and becomes dissipated.
In addition to wicks soaked with liquid, olfactory lures can take other forms. Similarly, different forms of traps can be used. Various insect traps, by reason of their physical shape, can have hanging attachments built into them or can integrally or by attachment include receptacles such as a dental wick holder as described above.
The holder must be fixed to the trap, or arranged to sit on a supporting surface, which complicates matters. Where a liquid or loose material lure is used, the lure must be carried in an upright container. Examples are shown, for example in U.S. Pat.No. 2,193,492-Richardson and U.S. Pat. No. 3,855,727-Cavoy. These patents disclose traps where a complex particular structure is employed for holding the lure in a trap and holding the lure in place. While it may be possible in a less complicated trap to simply put the lure on a supporting surface (e.g., the bottom), this has drawbacks. The trap cannot be tilted or inverted. Trap shapes are specifically designed to take advantage of instinctive behavior of insects (for example many insects always walk upwardly when they alight) and the lure location and path of air flow must be taken into account. Furthermore, where a large number of insects are to be trapped and killed, dead insects accumulate and interfere with air circulation around lure material if simply placed on the bottom of the trap. For these reasons, relatively complicated traps have been standard, with various chambers and complicated holders. Such complicated shapes are difficult or impossible to arrange inexpensively as needed to enable use of olfactory lure traps on a large scale.
One type of olfactory lure called Polytrap, manufactured by Wickhen Products, Inc., a division of Dow Corning Corporation, can be configured as a self-contained solid or tubular enclosed body that has a particular olfactory characteristic. This material permits olfactory lures, e.g., pheromone lures, to be made in a fairly large solid block, for example one or two grams, which is to be located in the trap. Solids are easier to handle than loose or liquid attractants, which must be held in a cup, pouch or other receptacle, for example closed by some sort of emitting membrane that controls release of the olfactory component. If the lure holder is embodied as a compound structure with an attendant shell, it would be helpful to build a hanging device on the compound structure and affix it in a manner that tolerates overturning of the trap, however, without substantial expense.
A benefit of using a Polytrap lure is that large amounts of active ingredients, such as one or two grams, are incorporated in this type of lure. The lure is a fairly large size and yet is a single polymer matrix type plug having no other physical members other than itself. The Polytrap lure emits attractant from all its exposed sides and need not have a wrapping or confining skin, net or like holder. The Polytrap lure needs to be held physically in place by a structure other than its own manufactured structure, preferably exposing the maximum possible area to air flow.
U.S. Pat. No. 4,642,936-Jobin et al shows a trap in which an attractive lure can be mounted immediately under a trap's top wall, by means of a cage-like cup that engages a complementary receptacle under the top wall. The cup is used with a pellet-type pheromone. The cage holds the lure above and clear of the area in which dead insects accumulate, but requires a particular mounting means. Due to the needed precision and complexity, this lure holder and trap combination is relatively more expensive than a single delta trap, preferably made of plastic, waxed cardstock or the like. The lure holder basket has no movable element for opening and closing the lure-holding space. The lure holder itself is specific to this trap and not generally useful for a variety of traps.
A variety of other holder and/or trap structures have screens or grids wholly or partly enclosing a bait or lure substance. U.S. Pat. No. 4,551,941-Schneidmiller has grid-like outer walls. A very open grid is disclosed in U.S. Pat. No. 254,800-Cohen. Screens shaped as cups are found in U.S. Pat. Nos. 983,977-Lilge and 995,280-Vernsey. U.S. Pat. No. 1,103,656-Campbell even uses a drawstring bag. These references do not employ a grid-like basket with an integrally hinged closure and tab mounting.